US2872896A - Liquid supplying means for hectographic copying machines - Google Patents

Description

Feb. 10, 1959 R. BROIWN 2,872,896

LIQUID SUPPLYING MEANS FOR HECTOGRAPHIC COPYING MACHINES Filed March 1. 1954 6 Sheets-Sheet l \NVENTOR Aoumw ZR BY 1 g (Mmv :ATTOR EYS Feb. 10, 1959 R. BROWN 2,872,896

LIQUID SUPPLYI NG MEANS FOR. 'HECTOGRAPHIC COPYING MACHINES Fil ed March 1. 1954 6 Sheets-Sheet H 1 8.? j I 1 l N l 31 C] 9 J k U. r 3:

INYENTOR R0; A ND -5 0 h/N Feb. 10, 1959 R. BROWN ,3

LIQUID SUPPLYING MEANS FOR HECTOGRAPHIC COPYING MACHINES Filed March 1;. 1954 e Sfieets-Sheet FIG. 3-.

INVENTOR' RoLAA/JJ BRO N 51%MM7 u ATTORNEYS Feb. 10, 1959 R. BRbwN 2,872,396

LIQUID SUPPLYING MEANS FOR. HECTOGRAPHIC COPYING MACHINES Filed March 1. 1954 6 Sheets$heet 4 I NVE N TO R Ram/v.0 3R0 w/v m zz w ATTORNEY Feb. 10, 1959 R. BRo'wN 2,372,396

mqum SUPPLYING MEANS FOR. HECTOGRAPHIC COPYING MACHINES Filed March 1. 1954 6 Sheets-Sheet 5 \NVENTQR R o 1. AND BRO W N BW ZW a! W ATT ORNEYS Feb; 10, 1959 R. BROWN 2,872,896

LIQUID SUPPLYING MEANS FOR HECTOGRAPHIC COPYING MACHINES Filed March 1. 1954 6 Sheets-Sheet 6 Foul/v0 mow/y United States Patent Ofiice 2,872,896 Patented Feb. 10, 1959 LIQUID SUPPLYING MEANS FOR HECTO- GRAPHIC COPYING MACHINES Roland Brown, London, England, assig'nor to Block & Anderson Limited, London, England, a British company Application March 1, 1954, Serial No. 413,327

7 Claims. (Cl. 118--249) This invention relates to hectographic copying machines of the kind in which a master sheet prepared in mirror script in hectographic ink is mounted on a rotary drum and copies are obtained on copy sheets which are moistened with a solvent for the hectog'raphic ink and are passed between the drum and a pressure roller.

The present invention is concerned with the means for moistening the copy sheets as they are fed to the drum. For this purpose use is made of a moistening roller constituting the upper of a pair of feed rollers, the moistening liquid being appliedto the moistening roller by means of a capillary pad which is in contact with the moistening roller.

An object of the invention is to provide a novel form of liquid supplying device for the capillary p'ad.

A further object of the present invention is to provide, in a machine of the type above referred to, improved means for controlling the rate of supply of moistening liquid to the pad whereby the liquid can be taken up by the pad at a substantially greater rate than normal for the purpose of priming the pad.

The pad is held in a holder the lower part of which is formed as or is attached to a conduit through which the moistening liquid is caused to pass during the operation of the machine, a pump associated with a reservoir pumping the liquid in at one end of the conduit and an outlet pipe at the other end discharging back into the reservoir, the conduit being a'pertured to permit liquid to pass to the capillary pad.

According to the invention means are also provided for shifting the capillary pad from a normal moistening position to a priming position whereby the rate of discharge of the fluid from the conduit outlet is checked and correspondingly the rate of liquid supply to the pad is increased. The outlet pipe is so'placed that in the normal operation it forms a weir at the outflow end' of the conduit to regulate and facilitate the supply of liquid through the apertures to the pad at the proper rate for copying, whereas when the pad holder is rotated out of the normal position into a priming position, the end of the outlet pipe is brought into contact with an obturator such as a sealing plate or cushion whereby the outlet is wholly or substantially obstructed so that the liquid delivered by the pump is constrained to pass through the apertures to the capillary pad in larger quantities to'prime'the pad. The conduit is conveniently constituted by acylindrical tube, the pad holder being. an open-ended box attached to the tube. The ends of the tube beyond the pad holderare received in slots in plates stationarily mounted on the machine, a spring clip associated with the pad holder urging the pad against the moistening roller and the tube against the ends of the slots. T he'pump, which is operated automatically from the mechanism for rotating the drum, is connected on its delivery side to the conduit by flexible tubing to permit of rotation of the pad holder from priman outlet pipe 32 which branches off from the tube 29 at a convenient level, for example about half way up,

ment from the pump. The outlet pipe discharges into a channel or gutter which drains intothe reservoir and 2 which is of such extent as to receive the liquid from the outlet pipe whether the pad holder is in the working position or in the priming position.

One embodiment of the'invention will now be described in greater detail with reference to the accompanying drawings, in which:

Figure l is a view of one side of the machine,

Figure 2 is a view of the other side,

Figure 3 is a plan view showing the feed-table end of the machine,

Figure 4 is a fragmentary transverse section showing the moistening mechanism,

Figure 5 is a detail view of the moistening pad arrangernent,

Figure 6 is a view looking at the left-hand end of Figure 5,

Figure 7 is a view looking at the right-hand end of Figure 5,

Figure 8 is an enlarged sectional view substantially on the line VIII-V1II of Figure 5,

Figure 9 is an enlarged cross-section through the pad casing and trough 33 taken in planes as shown by the line lX-IX in Fig. 3.

The constituent parts of the machine are journalled in or otherwise carried by two main side frames 1, 2 which are provided with side covers 3, 4 which are shown in position in Figure 4 but are removed in Figures 1 to 3 in,

order to show better the actuating mechanisms normally covered thereby. The hectographic master which is to be copied is mounted on a drum 5 which with an associated ing roller. The solvent for the hectographic ink is applied.

to the roller 10 by the upper end of an inclined damping pad 12, the lower end of which is supplied with the solvent. The roller 10, and with it the roller 11, is driven by the engagement of a toothed segment 13 with a gear wheel carried on the shaft of the roller 10 with the interpositioning of a unidirectional coupling. The rollers It It are thus rotated in the feed sense only, the unidirectional coupling permitting the return stroke of the segment 13 without corresponding movement of the rollers.

The segment 13 is carried by a radius arm Ml provided with a pin 15 engaging in a slot 16 in a link 17 attached to a crank arm 18 secured for rotation with the drum 5.

The pin and slot engagement permits of lost-motion at the commencement of the movement of the link 37; By

adjusting the rest position of the segment 13, the degree of lost motion can be varied and the instant at which the rollers 10, 11 start their feed movement is adjusted.

The capillary damping pad 12 is carried by a housing 28 through the lower part of which passes a tube 2? having a plurality of holes 30 distributed along the length of its upper wall so that the moistening liquid supplied through the inlet 31 to the tube 2% is distributed suiticiently uniformly along the length of the pad 12. The liquid reaching the pad is conveyed therethrough by capil lary action and isv applied to the roller 10. At the end remote from the inlet 31, the tube 29 is provided with from the bottom of the tube 29, so as to maintain an adequate supply of liquid to the pad whilst by-passing the surplus liquid when the housing 28 is so positioned that the pad 12 is in contact with the roller 10 (Figure 1). Thus a supply of liquid is r'etaine'd'in the tube 29, but

surplus liquid beyond the predetermined amount is discharged through the outlet 32. The outlet 32 discharges into a trough 33 from which a return pipe 34 extends to a reservoir 35 for the liquid. The liquid is supplied to the inlet 31 of tube 29 by means of a pump 36 provided with a flexible connection to the inlet 31. The pump is actuated during the rotation of .the drum by means of a lever 38 co-operating with a cam 39 secured for rotation with the drum. The stroke of the pump 36 and thus the quantity of liquid delivered can be adjusted by a lever 40 limiting the throw of the lever 38. The adjustment is made in such manner that the quantity of liquid delivered exceeds the quantity required for the copying operation, so that there is an excess in the tube 2) which flows over the weir formed by the angled connection of the outlet 32 with the tube 29. This surplus passes into trough 33 and thence via pipe 34 to reservoir 35.

The ends of the tube 29 are received in slots 50 in the side frames 1, 2 the lower ends of the slots forming bearings in which the tube 29 can turn about its own axis. To retain the pad housing 28 in its operative position in which the felt pad 12 is in contact with the moistening roller (Figures 1, 3 and 4), the housing 28 is provided with a latch 41 which is adapted to engage under a crossbar 47 extending between the side frames 1, 2. The latch 41 is resiliently loaded by a spring 42 extending between it and the housing 28. The spring 42 is shrouded by a casing 43 which is pivoted at 44 to the housing 23. The latch 41 is itself pivotally connected to the casing 43 by a pivot pin 45 which extends through a slot 46 in a mem-- ber forming part of or attached to the housing 28. This pin and slot arrangement'permits limited pivotal movement of casing 43 and latch 41 under or against the action of the spring 42. By raising the pad holder and pressing against the casing 43, the latch 41 is engaged under the bar 47, whereby the housing is secured with the pad 12 resiliently urged against the roller 10.

As shown in Figs. 2, 5, 6 and 7 and in greater detail in Fig. 9, the outlet pipe 32 from the pad housing 28 is curved and, viewed in side elevation, constitutes approximately a quarter of a circular ring. With the pad 12 in normal damping position against the roller 10, the outlet 32 is at such an angle that the liquid level can build up to the holes in tube 29 before liquid drains away through the outlet 32. In this way the angled outlet forms a weir to ensure that the correct proportion of the liquid is absorbed by the capillary pad and the excess drains into the trough 33. When however it is desired to prime the pad, as may be desirable when commencing operation after the machine has been out of use for a period sufiicient to allow the volatile solvent to evaporate from the pad, then the latch 41 is released and the pad holder 28 is swung upwardly through about 90 into the alternative position indicated in chain lines in Figure 9. In this position the end of the outlet 32 abuts against a sealing pad 48 affixed to the rear wall of the trough 33. Consequently little or none of the liquid delivered by the pump can return to the reservoir, so that the quantity pumped in excess of that necessary to fill the tube 29 is pumped through the holes 30 directly into the pad 12 which consequently becomes thoroughly moistened much more quickly than if the capillary action alone were relied on.

Feeding of the sheet to the pair of feeding rollers 10, 11 may be performed by hand, or it may be performed automatieally using the feed table and feed mechanism as shown in the drawings.

Adjustably carried on the feed table 19 are two paper guides each consisting of a side member 52 and a base member 53, the latter being adapted to underlie the pile of sheets to be fed. To enable the paper guides to be set at the requisite spacing and in the desired relationship to the master sheet to be copied, each guide is associated with a transverse slot 54 and is manually adjustable by 4 clamping means (not shown) co-operating with the said slots below the table. Towards the delivery end of the feed table, the side member 52 of each paper guide carries a guide block comprising a resilient clip portion 55 embracing the side member 52 and a facing block 56 secured to the sheetproximate face of the clip 55. The block 56 can be made of any suitable hard smooth-faced material presenting a surface over which the edges of the sheets can slide with little friction. A paper-board bonded and faced with a hard-surfaced material from the general class known as synthetic plastics is appropriate for the purpose. Towards the outward end of the feed table 19 the side member 52 of each paper guide carries a friction guide block comprising a resilient clip portion 57 embracing the side member 52, a forward extension 58 on the inner face of the side member 52 and integral with theclip 57, and a sponge rubber facing 59 attached to the sheet-proximate face of the clip 57 and the extension 58.

The side guides 52, 53 are adjusted so that the blocks 56 are exactly at the width of the sheets to be fed, so that the leading edges of the sheets are precisely located. The sponge-rubber blocks 59 frictionally engage the edges Of the sheets adjacent their trailing ends and facilitate the separation and feeding ofthe topmost sheet.

The copy sheet is advanced to the rollers 10, 11 by a feed mechanism operating on the pile of sheets to be held and aligned on the feed table 19 by the paper guides above referred to. This feed mechanism comprises a pusher 20 comprising a rubber pad carried by a cranked arm 21 journalled in a carriage 22 adapted to reciprocate on longitudinal guides 23 secured to the side frame 2. The reciprocation is derived from a cam 26 by a rocker 25 and is transmitted to the carriage 22 by a link 24. A spring 27 serves to maintain the follower end of the rOcker 25 in contact with the cam 26.

The transverse limb of the cranked arm 21 terminates in an end piece 63 which is journalled in the carriage 22. The said limb passes through a slot 69 in the side frame 2 and, to retain the end piece 63 in the carriage 22, a latch 65 pivoted on the carriage is urged by a spring 66 into a recess in the end piece 63. By suitably shaping the co-operating surfaces of the latch and the bottom of the recess, the spring 66 can be caused to augment the gravity pressure of the pad 20 against the top sheet. For convenience in introducing a fresh supply of sheets, the pusher arm 21- may be removed after releasing the latch 65.

The feeding operation is as follows:

During the rotation of the drum 5 the cam 26 rocks the rocker 25 and thereby reciprocates the carriage 22. During the forward motion of the carriage 22 the pusher pad 20 advances the topmost sheet of the pile until the leading end of this sheet is arrested at the line of contaet between a pair of feed rollers 10, 11, the upper roller 10 of which is moistened by the pad as above described. The further feeding of the sheet is taken up at this point by the rollers 10, 11 whose timing is adjusted as above mentioned by the segment 13.

If, as shown in the drawings, the sheets are fed from the stack by the reciprocating pusher member 20 which on its forward stroke thrusts the top sheet forward and on its return-stroke slides over the sheet surface, there may be a tendency for sheets which are waiting to be fed to be displaced rearwardly by the drag of the rearward motion of the pusher 20. To prevent this, the rear friction clip of each paper guide is provided with a back stop 70 extending at the rear of the stack of sheets.

I claim:

1. In a rotary hectographic copying machine of the kind wherein copies are taken from a master sheet having a mirroscript image formed in spirit-soluble transfer material wrapped round a printing drum, the combination with said drum of a pair of copy sheet feed rollers positioned before the printing drum, the upper one of the said pair being a moistening roller, moistcning means comprising an upwardly inclined capillary pad adapted to contact the said moistcning roller, a holder for the capillary pad, a perforated supply conduit for moistening liquid connected to said pad holder, an inlet at one end of said conduit, outlet means movably mounted at the other end of said conduit and shaped to permit overflow of excess moistcning fluid when the capillary pad is in contact with the moistcning roller, an obturating pad normally out of contact with the said outlet means, said capillary pad holder and conduit being pivotable about an axis parallel to the drum axis and having a normal position and a priming position, said priming position being achieved by pivotal movement of said capillary pad holder and conduit to remove the capillary pad from contact with the moistcning roller and into contact with the obturating pad whereby discharge of fluid from said outlet means is checked or prevented.

2. In a hectographic copying machine of the kind wherein a moistcning liquid for moistcning the copy, sheets is applied to the upper'one of a'pa'i'r of feed rollers, moistcning means comprising a capillary pad, a holder 'for said pad provided with a perforated supply conduit to receive moistcning fluid, an outlet offset from the axis of said supply conduit for discharging excess liquid from the conduit when the pad is in contact with the said upper roller, a trough to receive said excess moistcning fluid from the conduit, means for pivoting said pad holder and conduit between a normal position and a priming p0si- 7 tion, a sealing pad arranged in said trough, said capillary pad holder and conduit being pivotably mounted to bring the outlet of the conduit against the sealing pad in the priming position.

3. The moistcning means claimed in claim 2 wherein the pad holder carries a latch engageable with a fixed member of the machine for holding the pad in liquid transfer relation with the feed roller.

4. In a hectographic copying machine, means for moistcning copy sheets comprising a capillary pad, a holder for said pad, a perforated liquid supply conduit combined with said pad holder, means for pivoting said pad holder and conduit about the long axis of said conduit between a normal position and a priming position, an outlet for said conduit offset from the axis thereof formed as a weir for discharging excess liquid from said conduit when a level of liquid is attained in the conduit in the normal position sufiicient to allow liquid to reach the pad through the perforations, and obturating means for sealing said discharge outlet, said obturating means being effective only when the pad holder and conduit are pivoted into the priming position.

5. Moistening means for a hectographic copying machine of the kind wherein a moistcning liquid for moistening copy sheets is applied to the upper one of a pair of feed rollers, said moistcning means comprising a capillary pad, a holder for said capillary pad, said holder having a perforated supply conduit for applying moistcning liquid to said pad, pivotal mounting means for said pad holder and said conduit for permitting movement about an axis parallel to the axis of said upper feed roller between a first position where said capillary pad is in contact with said upper feed roller and a second position where said pad is out of contact with said upper feed roller, a liquid inlet for supplying moistcning liquid to .said conduit, a liquid outlet carried by and movable with said conduit for discharge of excess liquid from said conduit and stationary obturating means, said obturating means being disposed in a position which is spaced from said outlet when said pad holder and said conduit are in said first position whercbylsaid outlet is unblocked and effective to discharge excess liquid from said conduit, but which is effective to block said outlet when said pad holder and said conduit are in said second position whereby the supply of moistening liquid to said pad is increased.

6. The moistcning means claimed in claim 5 in which said liquid inlet is at one end and said liquid outlet is at the opposite end of said conduit, said outlet having an offset discharge channel, which, when the pad holder is in said first position, is at a level which allows the volume of liquid in said supply conduit to build up to a level reaching the perforations in said conduit so that the liquid reaches said pad and which acts as a weir to maintain the said level of liquid by allowing overflow of excess liquid from said outlet.

7. The moistcning means as claimed in claim 5 having a trough to receive excess moistcning liquid discharged from said conduit outlet and wherein said obturating means comprises a sealing pad fixed inside the said trough, the said outlet abutting against the said sealing pad when the pad holder is in said second position.

References Cited in the file of this patent UNITED STATES PATENTS 1,769,250 Arvidson July 10, 1930 2,036,972 Storck Apr. 7, 1936 2,083,042 Storck June 8, 1937 2,284,622 Morrison June 2, 1942 2,510,256 Robinson et al. June 6, 1950 2,533,574 Gerlach Dec. 12, 1950

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